The normal histology of the esophageal and gastric mucosae of the frog, Rana pipiens

Abstract

FIFTEEN FIGURESPreparatory to a histo-physiological investigation into the mechanism of mucus secretion in the frog stomach, a detailed account of the histology and cytology of this organ was sought. Although several descriptions of the frog's gastric mucosa were published before the turn of the century (see Gaupp, '04), a search of the subsequent literature disclosed no comprehensive report based on more recent staining methods. The present study, employing a variety of histological and histochemical techniques, was undertaken therefore to provide a more complete morphological picture of the gastric and esophageal mucosae of the frog than has hitherto been available. MATERIALS AND METHODSAdult male leopard frogs (Busla pipiens) averaging about 30 gm in weight were acquired from a Vermont dealer during the fall and winter. These were kept for short periods of time, without feeding, in a cool (18°C) dark room in a soapstone sink continually awash with a thin film of running water. The animals under study were pithed and the esophago-gastric segment of the digestive tract was removed and immediately fixed in Relly's, Bouin's or Stieve's fluids, or in 10%

Glycoconjugate histochemistry of the digestive tract of Triturus carnifex (Amphibia, Caudata)

“…In Rana esculenta, as in other ranoidean frogs, pepsinogen is mainly produced by peptic cells clustered in the oesophageal glands, whereas hydrochloric acid is mainly produced by oxyntic cells arranged in the gastric glands (Norris 1959;Suganuma et al 1981;Bani et al 1992;Gallego-Huidobro and Pastor 1996;Ferri et al 2001). In some non-ranoidean frogs, such as Bufo viridis (Liquori et al 2002), and in Caudata, such as Triturus carnifex, oesophageal glands are lacking and both components of the gastric juice are secreted by one type of cell, the oxynticopeptic cells, which are located in the gastric glands (Liquori et al 2005).…”

Histochemical and Immunohistochemical Analysis of the Stomach of Rhinella icterica (Anura, Bufonidae)

“…Although studies on bufonids are scarce, El-Salhy and coworkers [8] In R. icterica, the muscular layer showed similar pattern related to other amphibians as R. catesbeiana and X. laevis [51]. However, Norris [38] noticed that in R. pipiens the circular layer of muscularis is absent in lower portion of both fundic and pyloric regions.…”

“…Like in R. pipiens [38] (Norris, 1959) and R. aurora aurora [13], the stomach was characterized by two gastric regions: fundic and pyloric. Nevertheless, Gallego-Huidobro and Pastor [15] noticed that in R. perezi the fundic region is subdivided into upper and lower portions.…”

“…Liquori and coworker [22] suggest that differences In this study, oxynticopeptic cells revealed cytoplasmic acidophilic granules after staining with Gomori's trichrome. Norris [38] noticed that in R. pipiens the secretory granules of the oxynticopeptic cell are smaller and less numerous when compared to the pepsinogen granules of the frog esophageal glands.…”

Glycoconjugate histochemistry of Xenopus laevis fundic gland with special reference to mucous neck cells during development

“…Although amphibians are lower vertebrates, their adult fundic gland is basically composed of SMCs, MNCs, oxynticopeptic cells (OPCs), and endocrine cells (ECCs) (Norris, 1959;Ito, 1967;Geuze, 1971). Moreover, their fundic glands show a simple structure compared to those of mammals.…”